Pressure vessel for a motor vehicle

ABSTRACT

A pressure vessel is provided for a motor vehicle, having a fastening apparatus. The fastening apparatus is designed to connect the pressure vessel to a body of the motor vehicle. The fastening apparatus has at least two connecting pins and at least two bearings. In each case, one connecting pin is connected to a bearing at a connecting point. The connecting pins and/or the bearings are each connected to the pressure vessel in a pressure vessel attachment region and extend away from the outer surface of the pressure vessel. The pressure vessel attachment regions exhibit in each case an expansion. The connecting pin and the bearing are, in the connecting point, at least regionally shaped and arranged such that the expansion is kinetically guided with only one translational degree of freedom by way of a movement of the bearing and/or of the connecting pin.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §119 from German PatentApplication No. 10 2015 204 831.4, filed Mar. 17, 2015, 10 2015 206825.0, filed Apr. 15, 2015, and 10 2015 206 826.9, filed Apr. 15, 2015,the entire disclosures of which are herein expressly incorporated byreference.

This application contains subject matter related to U.S. applicationSer. No. 15/071,615, entitled “Pressure Vessel for a Motor Vehicle”filed on even date herewith

BACKGROUND AND SUMMARY OF THE INVENTION

The technology disclosed here relates, inter alia, to a pressure vesselfor motor vehicles. The pressure vessel may be, for example, a cryogenicpressure vessel or a high-pressure gas vessel in which fuel is stored.

Pressure vessels expand in a manner dependent on factors such as theinternal pressure p or the temperature T of the pressure vessel. Forthis reason, pressure vessels are attached to the body in accordancewith the fixed bearing-floating bearing principle. From the prior art,bearing arrangements with pressure vessel expansion compensation areknown, in the case of which the expansions of a pressure vessel in aradial direction R and in the direction of the pressure vessellongitudinal axis A-A are compensated by way of separate mechanisms.Such embodiments are relatively cumbersome and are therefore expensive.Moreover, they require a relatively large amount of structural space.Moreover, they are not capable of transmitting all forces and momentsfrom one end of a pressure vessel to another end of the pressure vessel.For example, the previously known solutions are not capable, in the caseof a pressure vessel arranged in the central tunnel of a motor vehicle,of transmitting forces in the direction of travel x in play-freefashion. Furthermore, moments about the vehicle transverse axis y andthe vehicle vertical axis z cannot be transmitted in play-free fashion.

It is an object of the technology disclosed here to reduce or eliminatethe disadvantages of the previously known solutions. Further objectswill emerge from the advantageous effects of the technology disclosedhere. The object(s) is/are achieved by way of a pressure vessel for amotor vehicle, having a fastening apparatus designed to connect thepressure vessel to a body of the motor vehicle. The fastening apparatushas: at least two connecting pins and at least two bearings. In eachcase, one connecting pin is connected to a bearing at a connectingpoint. The connecting pins and/or the bearings each are connected to thepressure vessel in a pressure vessel attachment region and extend awayfrom the outer surface of the pressure vessel. The pressure vesselattachment regions exhibit in each case an expansion, and the connectingpin and the bearing, in the connecting point, are at least regionallyshaped and arranged such that the expansion is kinetically guided withonly one translational degree of freedom by way of a movement of thebearing and/or of the connecting pin.

The technology disclosed here relates to a pressure vessel for storingfuel for a motor vehicle. A pressure vessel of this type may be, forexample, a cryogenic pressure vessel or a high-pressure gas vessel. Thepressure vessel may be used in a motor vehicle which is operated, forexample, with compressed natural gas (CNG) or with hydrogen (fuel cellelectrical vehicle). The cryogenic pressure vessel may store fuelpreferably in the liquid or supercritical state of aggregation. The fuelmay be stored in the cryogenic pressure vessel for example attemperatures of approximately 30 K to 360 K. High-pressure gas vesselsare preferably designed to store fuel permanently at a pressure of overapproximately 350 bar(g), more preferably of over approximately 500bar(g), and particularly preferably of over approximately 700 bar(g).

The pressure vessel includes a fastening apparatus, wherein thefastening apparatus is designed to connect the pressure vessel, at oneside of the pressure vessel, to a body of the motor vehicle. Here, apart of the body is to be understood to mean any suitable structure ofthe motor vehicle to which the pressure vessel can be fastened. Forexample, the at least one pressure vessel of the motor vehicle may bearranged in the central tunnel. Furthermore, however, the pressurevessel may also be accommodated elsewhere, for example under the rearseats.

The fastening apparatus may have, on one side or on one end of thepressure vessel, at least two connecting pins which may each beconnected, in particular rigidly, to the pressure vessel in a pressurevessel attachment region. The at least two connecting pins may extendaway from the outer surface of the pressure vessel. The connecting pinmay also be referred to as a connecting rod or connecting bolt. Theconnecting pin is preferably formed so as to be rigid or immovablerelative to the pressure vessel or relative to the body.

The at least two connecting pins may each be guided or received in abearing. The bearings or guides are particularly preferably suitable forpermitting a relative displacement between the connecting pins and thebearings or guides. Furthermore, the bearings may preferably be fixingmechanisms such as are likewise disclosed here.

In each case one connecting pin may be connected to a bearing at aconnecting point V.

Furthermore, as an alternative to the preceding refinement, thefastening apparatus may also, on one side or on one end of the pressurevessel, have at least two bearings which are each connected to thepressure vessel in a pressure vessel attachment region and which extendaway from the outer surface of the pressure vessel. This aspectconstitutes the kinematic reversal of the preceding aspect. Instead ofthe one or more bearings being arranged on the body, it is also possiblefor the one or more bearings to be arranged on the pressure vessel. Theat least two connecting pins would then be arranged on, and connectedto, the body. It is also possible for a combination (one bearing and oneconnecting pin) to be connected to the pressure vessel.

In the pressure vessel attachment regions, the pressure vessel mayexhibit in each case an expansion E and/or expand in said direction E.

The connecting pin and the bearing can, in the connecting point V, be atleast regionally shaped and arranged such that the expansion E iskinematically guided with only one translational degree of freedom byway of a movement of the bearing and/or of the connecting pin. Theexpansion E in the pressure vessel attachment region B is preferablythereby at least partially compensated. In other words, the expansion Ecauses a movement of the component (bearing or connecting pin) that isrigidly connected thereto. The component is, however, of such a formthat it can follow the movement of the expansion E such that, as aresult of the expansion E itself, no additional forces and/or moments,or only small additional forces and/or moments, are transmitted at theconnecting point V to the further component of the fastening apparatus(corresponding connecting pin or bearing).

A movement of the bearing and/or of the connecting pin with only onetranslational degree of freedom means that, during the translationalmovement in space, the coordinates x, y and z of the movement aredependent on one another and cannot be varied independently of oneanother. The only one translational degree of freedom may be a movementalong a straight or curved path. The exact profile of the path arisesfrom the vessel geometry, the expansion behavior thereof and thearrangement of the bearings/connecting pins.

In the case of the technology disclosed here, all other degrees offreedom are restricted. In this way, it is possible for a greater numberof force and/or moment components to be transmitted in play-free fashionalong the vehicle axes than in the case of previously known solutions.Furthermore, such a suspension arrangement or fastening apparatus for apressure vessel is easy to realize. It is preferable for four connectingpins to be provided on each side of the pressure vessel.

A special case is a linear or straight expansion E of the pressurevessel attachment region B. In the special case of a linear expansion E,wherein the angle α thus remains constant for all expansion states, theconnecting pins are at least regionally straight, and the then constantexpansion direction E may preferably be at least regionally collinearwith respect to the longitudinal axis of the connecting pins and/or ofthe bearings. By virtue of the fact that the expansion E, that is to saythe expansion caused, for example, by the change in pressure vesselinternal pressure or temperature, is parallel to the longitudinal axisof the connecting pins, only a linear movement takes place at theconnecting point V at each suspension point. It is thus possible forcomponents of particularly simple construction to be used.

The expansion E may run collinearly, or with a slight offset, withrespect to the axes of the connecting pins and/or of the bearings. Ifthe longitudinal axes of the connecting pins and/or of the bearings arearranged offset with respect to the expansion E, for example with anoffset toward the outside, it may be possible by way of such a structurefor any moments to be transmitted in a more effective manner. For themost part, the special case of the parallel arrangement of the expansionE and the longitudinal axes of the bearings/connecting pins will bediscussed below. The disclosed technology is, however, likewiseapplicable to translational movements with only one degree of freedomalong curved paths.

The at least two connecting pins and/or the at least two bearings may bearranged so as to be angled with respect to one another. If theconnecting pins and/or the at least two bearings are arranged so as tobe angled with respect to one another—that is to say not parallel withrespect to one another—it is possible for further forces and moments tobe transmitted. If the connecting pins and/or the bearings were arrangedparallel, it would not be possible for forces to be transmitted inplay-free fashion in the direction of the collinear axis (for example ofthe pressure vessel longitudinal axis).

The longitudinal axes of the at least two connecting pins and/or of theat least two bearings may be arranged at an angle β with respect to oneanother, which angle lies between 2° and 178°, preferably between 5° and90°, and particularly preferably between 10° and 50°. Depending on thedesign of the pressure vessel, the expansion E resulting from thepressure vessel loading may lie in these angle ranges. The resultingexpansion E can be predicted in an effective manner in advance by way ofsimulations and tests.

The longitudinal axes of the at least two fastening pins and/or of theat least two bearings are preferably arranged so as to be angled, thatis to say not parallel, with respect to the pressure vessel longitudinalaxis A-A. A degree of freedom along the pressure vessel longitudinalaxis A-A is then eliminated. The longitudinal axes of the at least twofastening pins and/or of the at least two bearings may be arranged at anangle α with respect to the longitudinal axis A-A of the pressurevessel, which angle lies between 2° and 178°, preferably between 5° and90° and particularly preferably between 10° and 50°. If the pressurevessel is installed, for example, in the central tunnel, it is thuspossible for forces to be transmitted in the vehicle longitudinaldirection. This task is performed, in vehicle architectures that arecommon nowadays, by longitudinal members. If the tank now partiallyperforms this task, it is possible for vehicle mass to be reduced,and/or for vehicle stiffness to be increased.

The bearings may be in the form of ball joints, in particular in theform of ball joints in which the connecting pins are received indisplaceable fashion and which furthermore permit a rotation of therespective connecting pins, similarly to the situation, for example, inthe case of ball joints in upper links of tractors. It is thus possiblefor the bearing arrangement formed from a bearing and a connecting pinto have not only one translational degree of freedom but likewise atleast one, preferably multiple, rotational degree(s) of freedom.

The fastening apparatus disclosed here may be provided on each side ofthe pressure vessel. The fastening apparatus may preferably have fourconnecting pins and four bearings, which are expediently arrangedconcentrically around the boss. The boss itself is thus easilyaccessible for any supply lines.

There is a demand to further improve, or actively change, the stiffnessof the body by way of the pressure vessel structure.

This is achieved, inter alia, by way of a pressure vessel for a motorvehicle, having a fastening apparatus, the fastening apparatus beingdesigned to connect the pressure vessel to the body of the motorvehicle. Here, the fastening apparatus may have at least one connectingpin which is displaceable relative to the body or relative to thepressure vessel. The connecting pin may, for example, be connected,preferably rigidly, to the pressure vessel or to the body. Inparticular, the connecting pin may be one of the at least two connectingpins discussed above.

The technology disclosed here furthermore includes at least one fixingmechanism which may be connected to the body or to the pressure vessel(that is to say inversely with respect to the connecting pin; that is tosay if the fixing mechanism is connected to the body, the connecting pinis connected to the pressure vessel, and vice versa). The fixingmechanism may be designed to at least temporarily fixedly clamp theconnecting pin.

The fixing mechanism is preferably rigidly or immovably connected to thebody or to the pressure vessel. The fixing mechanism may be designed toat least temporarily fixedly clamp the connecting pin when a controllertransmits a corresponding control signal. If the remaining degree offreedom in the direction of the longitudinal axis of the connecting pinor of the bearing is likewise blocked, the body is additionallystiffened. At the same time, by way of this regulable fixing mechanism,it is possible for any expansions, such as may arise, for example, as aresult of pressure changes or temperature changes in the pressurevessel, to be compensated.

It is particularly preferable for the connecting pin to be guided in thefixing mechanism. The fixing mechanism is preferably simultaneously theguide or bearing arrangement for the connecting pin. In other words, thefixing mechanism may preferably form the bearing discussed above. Thefixing mechanism is preferably arranged parallel to the connecting pin.It is preferable for at least two, particularly preferably four fixingmechanisms or bearings or guides to be provided on each side of thepressure vessel.

The fixing mechanism may be designed to fixedly clamp the connecting pinwhen the motor vehicle is subject to a dynamics demand above a firstthreshold value. It is thus possible, for example, for the motor vehicleto be additionally stiffened in the presence of a high dynamics demand.An increased dynamics demand may result, for example, from the roadcondition and the driving style of the vehicle driver.

The dynamics demand may be determined for example from the measurementvalues of a dynamic stability control (DSC) system. For this purpose,use may be made of sensors (rate of rotation sensors, transverseacceleration sensors, etc.) that are already installed in any case.

The fixing mechanism may be designed to not fixedly clamp the connectingpin when the motor vehicle is subject to a dynamics demand below a firstthreshold value, for example when the motor vehicle is at rest. If theconnecting pin is not fixedly clamped in this state, it is possible forany internal stresses induced by a change of internal pressure ortemperature of the pressure vessel to be dissipated again. This may takeplace in the state of rest without an additional displacement actuator.Moreover, unknown dynamic influences distort the adjustment.

The fixing mechanism may be designed to not fixedly clamp the connectingpin when the pressure vessel is being refilled. When the motor vehicleundergoes tank refilling, the expansion of the vessel changesconsiderably. If the fixing mechanism were to fixedly clamp theconnecting pin, it would be possible for undesired, possibly evendamaging loads to be transmitted to the body.

The fixing mechanism is particularly preferably fixed by at least onepiezo element. In particular, the at least one piezo element and thefixing mechanism may be designed such that the fixing mechanism preventsthe displacement of the connecting pin if no electrical voltage isapplied to the piezo element. Such elements can prevent the displacementof the connecting pin in a particularly rapid, inexpensive and precisemanner.

The fixing mechanism may be in the form of an electromechanicalactuator. In addition to a refinement in which the fixing mechanismmerely prevents the displacement, it is also possible for an actuator tobe provided which actively adjusts or displaces the connecting pin. Itis thus possible for the internal stress or the stiffness of the body tobe actively influenced. Depending on the driving mode preselected by thevehicle driver, the body is then made stiffer or softer. It ispreferably possible for the electromechanical actuator to be driven byat least one piezo element.

In a particularly preferred refinement, the electromechanical actuatoris an inchworm motor. An inchworm motor is a piezoelectric actuatorwhich, in its interior, can move or actuate a shank, in this case thefastening pin, with nanometer precision. For this purpose, the inchwormmotor has two gripping regions which are spaced apart from one anotherin an axial direction by piezo elements and which can firmly grip thefastening pin in alternating fashion and with a short time overlap.After gripping, the piezo elements change their length, whereby thefastening pin is displaced. With such an inchworm motor, it is possibleeven in the presence of high forces for the connecting pin to beactuated in a highly precise fashion and with continuous traction.Furthermore, the mechanical stress can be measured simultaneously. Thisthus constitutes an active strut which can positively influence thevehicle characteristics. A further advantage of the inchworm motor isthat the traction can be realized at all times.

The technology disclosed here also relates to a motor vehicle having apressure vessel presented here and having at least one controller. Thecontroller may be designed to release the at least one connecting pin ifan operating parameter of the fixing mechanism lies above an operatingparameter threshold value. For example, the operating parameter may bethe voltage of the actuator (for example piezo element, inchworm motor).This voltage may be representative of the mechanical load to which thepressure tank or the suspension arrangement of the pressure tank issubjected. Depending on the mechanical load, it can then thus be decidedby the controller whether the at least one connecting pin is released orfixedly clamped. Such a regulation system can be realized inparticularly simple and precise form.

The controller may furthermore be designed to release the at least oneconnecting pin if a collision is identified. A collision may beidentified for example on the basis of further detection systems of thevehicle. Such detection systems are known and are used in conjunctionwith airbags, for example. If the at least one connecting pin is notfixedly clamped by the fixing mechanism during a collision, it issubject to less mechanical load during the collision event. The amountof damage to the pressure vessel can thus be at least reduced.

Other objects, advantages and novel features of the present inventionwill become apparent from the following detailed description of one ormore preferred embodiments when considered in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a pressure vessel in accordance with anembodiment of the invention;

FIG. 2 is a schematic diagram of a pressure vessel similar to FIG. 1, inwhich the bearings are in the form of ball joints; and

FIG. 3 is a schematic diagram of a pressure vessel similar to FIGS. 1and 2, in which the bearings and connecting pins are interchangeablylocated.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a pressure vessel 100, which in this case is installed inthe vehicle longitudinal direction X in the vehicle, for example in thecentral tunnel. The pressure vessel 100 has a liner 110 and afiber-reinforced layer 120. At the two sides or ends of the pressurevessel, that is to say at the polar caps, there are provided fasteningapparatuses 140, 140′ which connect the pressure vessel 100 tocorresponding attachment points of the body, for example correspondingtransverse members adjacent to the front and rear axle supports. Thefastening apparatus 140 may be connected directly or indirectly to thebody.

FIG. 1 shows, in each case, two fastening apparatuses 140 on each side.It is particularly preferable for four fastening apparatuses 140 to beprovided on each end of the pressure vessel 100. Here, the fasteningapparatuses 140 include connecting pins 141, 142; 141′, 142′ andbearings 143, 144; 143′, 144′ in which the connecting pins 141, 142;141′, 142′ are displaceably guided. The bearings 143, 144; 143′, 144′and connecting pins 141, 142; 141′, 142′ of a fastening apparatus 140,140′ are, in this case, designed to be collinear. They both run at anangle α with respect to the pressure vessel longitudinal axis A-A. Thebearings 143, 144; 143′, 144′ are directly or indirectly connectedfixedly or rigidly to the body 200. The connecting pins 141, 142; 141′,142′ are in this case connected to the pressure vessel 100 in a pressurevessel attachment region B. In this case, the connecting pins 141, 142;141′, 142′ are led in through the fiber-reinforced layer 120. Otherfastening options for the fastening of the connecting pins 141, 142;141′, 142′ to the pressure vessel 100 are however also contemplated.

The double arrow E symbolizes the pressure vessel expansion in thepressure vessel attachment region B. Said expansion or expansiondirection E is a reaction of the pressure vessel 100 to changingoperating states, substantially to a changing internal pressure p of thepressure vessel 100. The bearings 143, 144; 143′, 144′ and connectingpins 141, 142; 141′, 142′ are arranged parallel to the expansion E. Ifthe pressure vessel 100 expands (or contracts) owing to a change ininternal pressure, this movement can be accommodated by the collinearlyarranged fastening apparatus 140, 140′. Owing to its design andarrangement, the fastening apparatus 140, 140′ makes do with only onedegree of freedom, namely the displacement along the connecting pinlongitudinal axis. The movement possibilities are therefore greatlyrestricted.

The longitudinal axes of the two fastening apparatuses 140, 140′ arearranged at an angle β, or so as to be angled, with respect to oneanother. Owing to the fact that the two fastening apparatuses 140, 140′are also rigidly connected to the pressure vessel 100, compensation ofthe pressure vessel expansion is duly provided, but a translationalmovement of the pressure vessel 100 as a whole along the longitudinalaxes of the fastening apparatuses 140, 140′ is prevented. Thus, allpossible movements of the pressure vessel 100 are prevented by thefastening apparatus 140, 140′. In other words, a pressure vessel 100with the fastening apparatus 140, 140′ disclosed here can compensateinternal pressure-induced expansions and simultaneously transmit forcesand moments in all directions in play-free fashion or substantiallyplay-free fashion. The pressure vessel 100 with the fastening apparatus140, 140′ disclosed here can thus transmit forces and moments from aregion close to the front axle to a region close to the rear axle, orvice versa. In particular, the fastening apparatus 140, 140′ disclosedhere is of comparatively simple and space-saving construction. Thefastening apparatuses 140, 140′ of one side are in this case arrangedsymmetrically. This, however, need not be the case. For example, itwould also be possible for the two fastening apparatuses 140 of theleft-hand side to have different angles α (cf. FIG. 3). The fasteningapparatuses 140, 140′ are preferably arranged concentrically and so asto be slightly spaced apart from the boss of the vessel.

FIG. 2 shows a pressure vessel 100 which is substantially identical tothat of FIG. 1. Therefore, only the difference will be discussed. Thebearings 143, 144; 143′, 144′ are in this case in the form of balljoints, in which the connecting pins 141, 142; 141′, 142′ are arrangedin displaceable fashion. The ball joints make it possible for theconnecting pins 141, 142; 141′, 142′ to rotate around the central pointof the ball joints. The ball joints improve the displaceability of theconnecting pins 141, 142; 141′, 142′. Since the connecting pins 141,142; 141′, 142′ are however clamped at the other end, the fasteningapparatuses 140, 140′ remain capable of transmitting forces and momentsin (substantially) play-free fashion.

FIG. 3 shows a pressure vessel 100 which is substantially identical tothose in FIGS. 1 and 2. Therefore, only the differences will bediscussed. As shown at the left-hand end of the pressure vessel 100, thearrangement of the bearings 143, 144; and connecting pins 141, 142; mayalso be interchanged. That is to say, it is also possible for thebearings 143, 144; to be clamped on the pressure vessel 100, and for theconnecting pins 141, 142; to be connected to the body 200. In thisrefinement too, it would be possible for ball joints to be provided. Acombination of differently arranged components 143′, 144′, 141, 142; ofa fastening apparatus 140′ at one end of the pressure vessel 100, as isshown for example at the right-hand end in FIG. 3, would self-evidentlyalso be conceivable. In this case, the two ends are of symmetrical form.At the right-hand end, some reference designations have been omitted forthe sake of simplicity.

In FIGS. 1 to 3, it is possible for the bearings 143, 144; 143′, 144′,and/or also fixing mechanisms (the fixing mechanisms also beinggenerally designated as 143, 144; 143′, 144′) in addition to thebearings 143, 144; 143′, 144′, to be provided. The fixing mechanismspreferably guide the connecting pins 141, 142; 141′, 142′. The fixingmechanisms or fixing elements are designed to at least temporarilyfixedly clamp the connecting pin 141, 142; 141′, 142′. It is notimperatively necessary for the fastening apparatuses 140, 140′ to run soas to be angled with respect to one another for this purpose. It wouldalso be possible for them to run parallel with respect to one another.This aspect of the technology disclosed here is thus independent of thearrangement of the fastening apparatuses 140, 140′. The fixingmechanisms are thus capable of selectively enabling or blocking at leastone degree of freedom, in particular the displaceability along thefastening apparatus longitudinal axis. Thus, scalable stiffness of thebody is realized, which can be adapted for example in accordance withthe dynamics demand. If the vehicle driver switches into a sport mode,it is possible for the vehicle to fix the connecting pins 141, 142;141′, 142′ by way of the fixing mechanisms, such that forces and momentscan be (better) transmitted via the pressure vessel 100. At the sametime, the selective fixing makes it possible for any internalpressure-induced pressure vessel deformations to be able to becompensated, without undesired internal stresses arising in the vehicle.In a simple refinement, it is possible for the fixing mechanisms tomerely fixedly clamp and release the connecting pins 141, 142; 141′,142′.

In a further refinement, the connecting pins 141, 142; 141′, 142′ areactively displaced by an electromechanical actuator. In such anembodiment, it is possible for the body stiffness to be adjusted in aprecise manner at any time by way of the pressure vessel 100, which isused as an active strut. In particular, piezo elements and inchwormmotors are suitable for imparting the possibly high forces for thedisplacement with the required precision.

The bearings 143, 144; 143′, 144′ and the connecting pins 141, 142;141′, 142′ of a fastening apparatus 140, 140′ are of collinear andstraight form in FIGS. 1 to 3. This, however, need not be the case. Itwould likewise be contemplated for the connecting pin 141, 142; 141′,142′ to have an S-shaped profile in the region between bearing 143, 144;143′, 144′ and pressure vessel attachment region B, and for that sectionof the connecting pin 141, 142; 141′, 142′ which is received in thebearing 143, 144; 143′, 144′ to run parallel to the axis of theexpansion E. Such an offset would possibly be advantageous for thetransmission of higher moments from the body to the pressure vessel. Itwould likewise be possible for the expansion E to take place not in astraight fashion but in a curved fashion. Then, the connecting pin 141,142; 141′, 142′ and/or the bearing 143, 144; 143′, 144′ would, at theconnecting point V, be shaped such that it guides the curved expansion Eby way of a translational movement with one degree of freedom.

Where the fastening apparatus, connecting pin, bearing, etc. componentsare referred to here in the singular, this is at the same time alsointended to jointly disclose a multiplicity thereof. Furthermore, thetechnology disclosed here also encompasses a motor vehicle having atleast one of the pressure vessels disclosed here and having a controllerfor controlling the pressure vessel, and possibly for controlling thefixing mechanism.

The above description of the present invention serves merely forillustrative purposes and not for the purposes of restricting theinvention. In the context of the invention, various changes andmodifications are possible without departing from the scope of theinvention and of its equivalents. The aspects relating to the spatialarrangement of the fastening apparatuses 140, 140′ relative to thepressure tank 100 are independent of the aspects relating to the fixingmechanisms 143, 144; 143′, 144′. The two aspects can therefore also beclaimed independently of one another. They are, however, preferably usedin combination.

The foregoing disclosure has been set forth merely to illustrate theinvention and is not intended to be limiting. Since modifications of thedisclosed embodiments incorporating the spirit and substance of theinvention may occur to persons skilled in the art, the invention shouldbe construed to include everything within the scope of the appendedclaims and equivalents thereof.

What is claimed is:
 1. A pressure vessel for a motor vehicle,comprising: a fastening apparatus configured to connect the pressurevessel to a body of the motor vehicle, the fastening apparatuscomprising at least two connecting pins and at least two bearings,wherein in each case, one connecting pin is connected to a respectivebearing at a connecting point, the pressure vessel has pressure vesselattachment regions, each region having either a connecting pin or abearing connected to the pressure vessel and extending away from anouter surface of the pressure vessel, and the pressure vessel attachmentregions exhibit, in each case, an expansion, and the connecting pin andthe bearing at the connecting point are at least regionally shaped andarranged to kinetically guide the expansion of the pressure vesselattachment region in only one translational degree of freedom viamovement of the bearing and/or the connecting pin.
 2. The pressurevessel according to claim 1, wherein in the pressure vessel attachmentregions the pressure vessel has an expansion direction parallel tolongitudinal axes of the connecting pins and/or the bearings.
 3. Thepressure vessel according to claim 2, wherein the longitudinal axes ofthe at least two connecting pins and/or the at least two bearings arearranged at an angle with respect to one another.
 4. The pressure vesselaccording to claim 1, wherein the longitudinal axes of the at least twoconnecting pins and/or the at least two bearings are arranged at anangle with respect to one another.
 5. The pressure vessel according toclaim 2, wherein the longitudinal axes of the at least two connectingpins and/or the at least two bearings are arranged at an angle withrespect to one another in a range between 2° and 178°.
 6. The pressurevessel according to claim 2, wherein the longitudinal axes of the atleast two connecting pins and/or the at least two bearings are arrangedat an angle with respect to one another in a range between 5° and 90°.7. The pressure vessel according to claim 2, wherein the longitudinalaxes of the at least two connecting pins and/or the at least twobearings are arranged at an angle with respect to one another in a rangebetween 10° and 50°.
 8. The pressure vessel according to claim 1,wherein longitudinal axes of the at least two fastening pins and/or ofthe at least two bearing are arranged so as to be angled with respect toa longitudinal axis of the pressure vessel.
 9. The pressure vesselaccording to claim 1, wherein longitudinal axes of the at least twoconnecting pins are arranged at an angle with respect to a longitudinalaxis of the pressure vessel, which angle lies between 2° and 178°. 10.The pressure vessel according to claim 1, wherein longitudinal axis ofthe at least two connecting pins are arranged at an angle with respectto a longitudinal axis of the pressure vessel, which angle lies between5° and 90°.
 11. The pressure vessel according to claim 1, whereinlongitudinal axis of the at least two connecting pins are arranged at anangle with respect to a longitudinal axis of the pressure vessel, whichangle lies between 10° and 50°.
 12. The pressure vessel according toclaim 1, wherein the at least two fastening pins are guided, in eachcase, in a respective bearing.
 13. The pressure vessel according toclaim 12, wherein the at least two bearings are ball joint bearings. 14.The pressure vessel according to claim 1, wherein one fasteningapparatus is provided on each side of the pressure vessel.
 15. Thepressure vessel according to claim 1, wherein: the fastening apparatuscomprises four connecting pins and four associated bearings, and thefour connecting pins and the four associated bearing are arrangedconcentrically around a boss of the pressure vessel.